Tire regrooving machine



May 17, 1960 c. G. RlcHNER TIRE REGRoovING MACHINE Filed April 18. 1956 4 Sheets-Sheet 1 May 17, 1960 c. G. RlcHNER 2,936,828

TIRE REGRoovING MACHINE Filed April 18, 1956 4 Sheets-Sheet 2 IN VEN TOR.

May 17, 1960 c. G. RICHNER TIRE REGRoovING u/IACHINE 4 Sheets-Sheet 3 Filed April 18, 1956 v INVENTOR. CIV/41911.55' GOM/VK/f/Vf? May 17, 196@ C. G. RlcHNER 2,936,828

TIRE REGROOVING MACHINE Filed April 18, 1956 4 Sheets-Sheet 4 3 WAY SWITCH 2,936,828 v TIRE REGRoovlNG MACHnrE Charles G. Rahner, Palmyra, NJ.

Application April 18, 1956, Serial No. 579,073

z claims. (ci. 151513) The present invention relates to the machines commonly employed for the purpose of cutting grooves in used tires, and is concerned primarily with mechanism forA moving the tire being worked on under power during the cutting operation.

vAt the present time, it is common practice, after the tread of a tire has worn smooth, to recut grooves in the exposed surface to provide, in effect, a new tread. Such grooves ordinarilyv are either straight or zigzag, depending on the nature of the tread desired. A machine of the .type with which this invention is concerned ordinarily comprises a framework in which a tire to be worked upon is adapted to be supported for rotation, together with a knife which engages thetire, and power means for rotating the tire to render the knife effective. `Ifla straight groove is to be cut, the knife is held in a fixed position .for that particular groove. On the other hand, if a' zigzag or sawtooth groove is to be cut, the knife must be'reciprocated from side to side as the tire is' driven under power.

With lthe machines now available, considerable diiculty is being experienced in-rotatingthe tire under power. This action should be positive inevery respect, and must be/ susceptible of accurate control. Moreover, when'a zigzag groove is being cut, thetire should be rotated with an intermittent motion so that the tire is momentarily at rest each time the knife reaches one of its side limits of movement; otherwise, a wavy groove-will result, which is undesirable as compared to a Ysawtooth* groove having sharpcorners. A

f With the foregoing conditions inmind,y the present in-,.

vention has in view as its foremost objective the provision of a new and improved tire regrooving machine of the character indicated which includes no vel means for driving the tire, and which means is positive of operation,

accurately controlled, and aiords the desired intermittent motion. i More in detail, the invention has as an Vobject the provision, in a tire regrooving machine of the type noted, of l tire-driving mechanism which-consists essentially of a roller havinga roughened surface which engages the tire and vwhich Aroller is drivable'mounted on a shaft. Also mounted on the shaft are two-oppositely arranged oneway clutch devices. lA hydraulic cylinder-andpiston assembly yhas its piston operatively connected to these clutch devices so that,jas the piston is reciprocated, the roller is rotated with an intermittent motion,and a ing mvementimparted-to the tire. -v

`United States Patent `Still another object is to provide, in a lmachineofY the-- character aforesaid, a drive forthe tire in which each ofthe one-way clutches includes a pinion, wit-h'each pinion meshing with a rack, :with the two racks being connected to the piston, o f the piston-and cylinder. as-

sembly.

vStill another object of the invention is to provide, in a tire-regrooving machine'of the type aforesaid, a knife which is reciprocated from side to side' under the" inu'- encel of a'second hydraulic cylinder-and-piston assembly, v

with the operation of this second cylinder-and-piston assembly synchronized with respect to the first hydraulic susceptible of accruate positioning for the cutting of each groove. Thus, another object is to provide, in a machine of the character indicated, a knife which is adjustably mountedon its driving rod for a course adjustment, together with the mechanismfor providing a fine adjustment.

Still another object in view is to provide a tire-regrooving machine of the type aforesaid in which both the hydraulic cylinders are'included in a hydraulic circuit, with the circuit including a solenoid-actuated four-way valve. This valve controlsthe delivery of the hydraulic medium toA the opposite' ends of the two cylinders, Ywith the solenoids of the valveV beingiunder the control of either one of two sets of limit switches. When one set of limit switches is effective, both 'of the cylinders are rendered effective. On `the other hand, when only the hydraulic cylinder which drives thetire is to be used, the other set of limit switches is effective. In accordance with the present invention, one of these sets of limit switches is associated with the mechanism for reciprocating the knife; while the other setis associated with the hydraulic cylinderfor driving the tire. Y

Still another object of the invention is to provide new and'improved means for detachably mounting the knife in position. These knives',.which are of U-shaped formation, often., become wornfand broken and must be replacedffrom'time to time. It is important and highly desirable 'that the knife litself be easily taken out and' replaced by a new one. 1

Various other more detailed` objects and advantages of the invention, such as arise in connection with carrying out the vabove-noted ideas in a practical embodiment,

will Ain part become apparent and in part be hereinafter stated fas 4the description of the' invention proceeds'.

The invention, therefore, comprises a tire-regrooving machine whichA includesas a characteristic element a roller which'drivably engages the tire and which roller is rotated with an intermittent motion from a hydraulic cylinder-and-piston assembly through the medium of two ,one-wayclutches.' Aknife is reciprocated from a second hydraulic cylinder-and-piston assembly, and the operation of the two hydraulic cylinders is synchronized. The invention also embraces other novel, more detailed features.

and' with parts omitted. This view illustrates the driving roller and the knife, together with its associated mechanism. s

Figure 4 is another view taken on an enlarged scale .as a` front elevation ofthe knife and its associated mechanismr Figure 5 is an enlarged detailed showing of the limit switch -arrangement that is associated with the knife.

'Figure 6 is an' enlarged detailed perspective of onel ,Forafull 'and more complete understanding of the inend of the driving roller, vthe hydraulic cylinder-andpiston assembly therefor, the driving connections between the two, and the limit switch arrangement associated therewith.

Figure 7 is an enlarged detailed elevation ofthe knife.

and its mounting. 4

Figure 8 is a section taken on an enlarged scaley through a part of the knife mounting.

Figure 9 is a side view, mostly in elevation, depicting how the carriage for the knife `is maintained in an upraised position; and l Y.

Figure l is a diagrammatic view depicting the hydraulic circuit and wiring diagram that is utilized in the,

machine. A

Referring now `to the drawings, wherein like reference characters denote corresponding parts, and first more particularly to Figure l, the tire-regrooving machine of this invention is therein illustrated as including a framework, which is referred to in its entirety by the reference.

character F. The framework F comprises. two metallic tubular members 11 and 12,`which are arranged inthe spaced relation depicted in Figure 2 andV which are maintained in this relation by a top crossbar. 10 having bosses 13 at its opposite ends, with thebosses. 13 being formedY with openings which receive the members 11 andV 12, respectively. Adjacentto the bottom, the members 11 and 12 are connected by a rod 14, which -is disposed at.

a slight angle with respect'to the horizontah for a purpose to be later pointedl out.

The frame F also includes a pair of short legs-*15, which are secured to the members 11 and 12 substantially mid; way thereof in any preferred manner, such as by being welded thereto. These legs 15 are also lpreferably tubufv lar, andare connected adjacent to their lower ends by a cross rod 16 which has substantially the same angle of inclination as the cross rod 14.

A roller 1'7 is freely journalledon the rod 14, and has iiange 18 at the side disposed towards the framemernber 12. A second roller 19 is similarlyV journalled on the rod 16, and has a ange 18 similar to the ange 18 on the roller 17. When a tire, such as shown at T, is positioned in the machine, the inclined disposition of the rollers 17 and 19 will cause the tire to tend to moveV towards the frame member 12. This aids in the accurate positioning of the tire, as will later become apparent.

A cross head 20 is formed with bosses 21 at its opposite ends. These bosses 21v are formed'withl passagesy which slidabiy receive the frameV members 11 and 12. Thus, the cross head 20 is slidably and adjustably mounted on.

the frame. A screw stern 22 has one endA rotatably anchored to the cross head 20, as indicated at 23 in Figure 1; and its upper free end is provided 'with a handwheel 24. This screw stem 22 passes through a threaded opening in a boss 25 carried by the crosspiece 10. It-is evident that the handwheel 24 may be rotated to raise or lower the cross head 20.

An arcuate roller support 26 is secured to the crosshead 2), and extending radially downward therefrom is a pair of stub shafts 27. Rotatably mounted on these stub shafts 27 are conical rollers 2S. These conical rollers engage one side of the tire T, as shown in Figure 2, and cooperate with the flanged rollers 17 and 19 in maintaining the tire in position.

VThe driving roller Referring now more particularly to Figures3, 6, and 9,

vmounted on the shaft 31 to provide driving movement the free end of a piston 3S.

The piston 38is included as a part of a vhydraulic cylinder-and-piston assembly, such as shown` at 39. A hydraulic conduit 40 is connected to one end ofthe cylinder 39 by the fitting shownat 41; while a second hydraulic conduit 42 is connected Vto the upper endof the cylinder 39 by a fitting 43, whichmay also carry a flow-control valve, shown at 44. V

It is evident that, when the hydraulic medium is admitted to the upper end of the cylinder 39 under pressure, the piston 38 is moved` downwardly. On the other hand, when the hydraulic medium is admitted under pressure to the lower end, the piston 38 is moved upwardly. In order to achieve an accurately controlled balance in the operation of the piston 38, a tab 45 is connected to the crosspiece 37. Arod 46 extends through an opening in Vthe tab 45 and hask its upper end anchored to a lugv 47 carried by the cylinder39. The lower endV of the rod 46 isthreaded and carries a nut 48. An expansion coil spring 49 isinterposed between the nut 48 and tab 45 about the v l rod 46 below the tab 45; while a second expansion coil spring 50 is disposed about the rod 46 above the tab 45 and bears against the tab 45 at one endandat a stop 51 at the other end, with the stop 51 being carried 'by the rod 46.

With the two one-Wayvclutch devices being properlyA arranged, it is evident that, on the downward stroke of the piston 3S, the rack bar 35 and pinion 33 are effective to. driveV thevk shaft 31v and `roller 32 in the direction of the arrow of Figure 6. During this downwardstroke,v the.-

vone-way clutch device associated with the pinion 34 renders the latter ineffective. However, on the up-stroke ofthe piston 38, the pinionl 33 is rendered ineffective,` while the .pinion 34 becomes effective to continuethe drive in the same direction. However, there is a brief pause at the moment when the piston 38 reaches the end of its strokeVv and the clutch devices change from their effectiveto-ineifective positions, and vice versa.

`Needless' to say, appropriate guiding structure is pro vided for maintaining the rack bars 35 and 36in effectiveY engagement withV theV pinions 33 and 34. A lug 52.is carried at the lowerv end ofthe rack bar 36, from which Yit outstands, and is adapted for cooperation with contacts 53 andl 54of a pair of limit switches 55v and 56,v to be laterv described..

Y The knife VReferring now more particularly to Figures 3, v4, and 9, a pairl of L-shaped brackets 57 is pivotally mounted, asi4 indicated at 58on the outer ends of thebracket arms 29. These, brackets 57 present forward upstanding legsl 59 which are connected at the top by a crossrod 60. A catch in the form of a leaf spring 61 has one end anchored to the crosshead 20;,and its other endgis formed as a detent for engagement with the crossrod 60 to maintain the. knifeassembly in theupraisedposition depictedby` the,l broken .lines in Eigure- The lower. portions. of theless.- 59 are" formed with openings through which passes a, knife Arod 62..-

A bracket 63` is connected tol the outery side-of. one of .the L-shaped brackets 57, `as shownin Figure y3; andy this conduit 67 is connected to the other end'of the cylinderV 64'by a'tting68. The cylinder 64 also carries at asses-82 appese nas a las Vf am 69' allan, 'which maybe* 62 carries a knife assembly, whichV is referred .toY in its entirety by the reference characterlifand which, is shown in some detailin Figures 7 and Aknife support 71 is adjustably mounted on the'rod62 and is adapted-'to beY held in'an adjusted position by' setscrew 72j. VIhe knife support 71 includes a cross flange' 73, from'which depends a central,rvertical flange 74. A plurality of shims 75 is disposed 'on opposite sides of the flange and maintained in assembled relation with'respect thereto through the medium of two side plates `76 and 7 7, which vare carried byheaded bolts 78 and79 which pass through openings in theshims75 andilange 74,- respectively. 'I'he side plate 77 is formed with a threaded opening 80, in which is received a threaded plug 81 having a central recess adapted to receive the endof an Allen wrench 82. The knife proper is shown at ,83 and is of a U-shaped formation. 'Ihe legs of the U are received betweenk the shims 75, as shown in YFigures 7 and 8. When it is desired to remove the knife 83, the Allen wrench 82 is availedA of to unscrew or, loosen theplug 81. This relieves the pressure on the shims and makes it possibile to remove .the knife and inserta new one. After the new knife -has lbeen positioned, the plug 81 is tightened v itis connected to a line 123 that is connected to one side by the Allen wrench, and the knife 83 is securely'held.

It is evident ythat the position of" the knife may be adjusted by varying the number of the shims. i

Referring now lmore particularly to Figures 3, 4, andv 5, a base plate 84 is shown as secured to-cthe outer side of one of 'the brackets 57'; Outstanding fromths base plate 8.4is'a Pair Ofg-rQdS A85A and 86... which are connected at their outer ends by an endpiece 87. A switchbox 88 is slidably mounted on the rods 85 and 86. A screw stem 89 has one end rotatably connected to the switchbox 88; and its other end passes through a threaded opening in the endpiece 87. The screw stem 89 carries an operating member 90 at its free end. Obviously, the member 90 may be rotated to adjust the position of the switchbox 88 as an entirety.

Referring now more particularly to Figures 4 and 5, a turnbuckle screw stem 91 is shown as being mounted within the swtchbox 88. This turnbuckle screw stem 91 has oppositely threaded sections 92 and 93. It carries an operating member 94 exteriorly of the switchbox. A microswitch 95 having a contact 96 is mounted on the threaded section 92; while a second microswitch 97 hav ing a contact 98 is mounted on the threaded section 93. An abutment member 99 is secured to the knife rod 62 and is adapted to move between the contacts 96 and 98 of the limit switches 95 and 97. It is evident that the relative distance between the contacts 96 and 98 may be adjusted by rotating the operating member 94..

Hydraulic and electric circuits Referring now more particularly to FigureV 10, the hydraulic and electric circuits which control the driving of the roller 32 and the reciprocation of the knife 83 will bc described. A tank for an appropriate hydraulic medium is'jshown at 100. Mounted on this tank 100 is a motor 101 which drives a pump 102. From the pump 102 there extends a conduit 103 to a four-way valve that is represented at 104. A return or drain line from the valve 104 to the tank 100 is shown at 105.

The details of the valve 104 are not here described in detail because such valves are purchasable as such on the open market. It is suicient to point'out that the valve 104 includes a pair of Ts 106 and 107 and a movable valve member which is reciprocal under the influence of the solenoids 108 and 109.

It will be noted that the conduit 65 is connected to one side of the T 107; while the conduit 42 is connected to the other side of this T. Likewise, the cond-uit 67 is connected to one side of the T 106; while the conduit 40 is connected tothe other' side of the T' 10.6. VA control 'valve 110 may be included in the conduit 42. j

A lthree-way switch is represented diagrammatically'at 111. 'I'he details of this three-way switch are also herein not illustrated because such switches are well-known'and may be purchased as such on the open market. It is sufficient to point out that' the switch 111 is connected by.

lines 112 and 113 tothe power lines 114 and 115, the

gether by a line`u116, whichV is in turn connected to a terminal of switch 111Tby/ a line V117. From the other side of the switch 97, a line 118 extends to a pointY 119, where it is .connected to a line 120., This line 120 is connected to one side of the switch 56 and goes back through the coil of the Vsolenoid 109 to a terminal of the switch 111'. Another line 121 is connected to the other side of the switch 95 and extends to a junction point 122, where of the switch 55.` From this'junctionpoint 122 a line 121 is continued through the coilA of the solenoid 108 to av junction point 124, where it is connected to the line 120 and hence back to the switch 111.

One side of each of the switches 55 and 56 is connected by a line 125. This line 125 is in turn connected by a line 126 with a terminal in the switch 111.

Operation .It willi be understood that, with the current turned off, the motor 101 is de-energized and the entire machine is at rest. In this condition,-the three-way vswitch 111'"i's turned to Oif." AMor'eovenilt is evident that the knife assembly, which'iscarried bythe brackets 57, may lite' savungupwardlyrs'o that the r'od"60-engages lthe spring 61* to maintain the knife assembly upraised. The machine is now in position to have a tire T positioned therein. The tire T is so positioned that it rests lagainst the rollers 28 at the top and the anges 18 of the rollers 17 and 19 at the bottom. It will first be assumed that it is desired to cut only a straight groove in the tire. In such case, the mechanism which reciprocates the knife should be rendered ineffective. Thus the valves 69 and 70 are closed to take the cylinder 64 out of operation; and the I switch 111 is turned to the position which renders the y and moving the support 71 to a desired position ouA the rod 62, after which the setscrew 72 is tightened. A

further fine adjustment may be achieved by availing of the operating member 90 to adjust the position of the switchbox 88 as an entirety. If it is desired to vary the length of the stroke, the distance between the limit switches 95 and 97 may be adjusted through the medium of the operating member 94.

The valves 69 and 70 are opened and the 4switch 111 moved to the position which renders the limit switches- 95 and 97 effective. When the abutment 99 engages one of the contacts 96 and 98, one of the solenoid coils 108 or 109 is de-energized, While the other is energized. This operates the four-way valve so that the hydraulic medium under pressure is delivered to one end of each of the cylinders 39 and 64. When the abutment 99 strikes the other contact, the energzation of the solenoids is reversed, which atfects the four-way valve to cause the lhydraulic medium to be delivered under pressure to the other ends of the Vcylinders 39 and 64. Thus it is evident 21S-*esas that the invention isenot to be limited to the exact mech` anisms, devices, land circuits illustrated and described, because various modifications of these details may be provided in putting the invention into practice within the purview of the. appended claims.

' What is claimed iszv f '1. In a tire-regrooving machine, avsupporting frame, means carried lby said frame for supporting a tire in position for rotation, a knife mounted on said frame efor lateral reciprocation, a hydraulic cylinder-and-piston assembly forreciprocating said knife,runder power in opposite directions, a tire-driving roller having a roughened surface adapted to frictionally engage the tread surface of a tire `in said frame to rotatably drive the tire while said knife is in operative engagement therewith, a hydraulic cylinder-and-piston assemblyfor driving said roller withl position for rotation, a knife mounted on said frame' for' lateral reciprocationa hydraulic cylinder-and-piston assembly for reciprocating said knife under power in oppo site directions, a tire-driving roller having a roughened surface adapted to frictionally'engagethe Itread surfaceh of a tire in said frame to rotatably drive the tire whil'sid., knife. is Yin. operative engagement therewith, a hydraulic cylinder-and".'pistonv assembly for driving said roller with an intermittent,motionvat'the Sametime said knife is re ciprocated,and,'a'valve controlling theV delivery of hydraulic mediumto'fboth said cylinders wherebywthe 'refv ciprocating motion ofA said. knife `and the intermittent motion of said roller are synchroniged,

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